Method of and apparatus for recording marine conditions.



H. T. BARNES.

METHOD OF AND APPARATUS FOR RECORDING MARINE CONDITIONS.

APPLICATION FILED mum, 1911.

1,022,526, Patented-Apr. 9, 1912.

2 SHEETSSHEET 1.

FIG:

WITNESSES INVENTUFI H. T. BARNES.

METHOD OF AND APPARATUS FOR RECORDING MARINE GONDITIONS.

APPLIGATION FILED MAILG, 1911.

Patented Apr. 9, 1912.

2 SHEETSSHEET 2.

m GE E w a WITNESSES INVENTDH H.T. BAHNES HOWARD TURNER BARNES, OFMONTREAL, QUEBEC, CANADA.

METHOD OF AND APPARATUS FOR RECORDING IV IARINE CONDITIONS.

Specification of Letters Patent.

Patented Apr. 9, 1912.

Application filed March 6, 1911. Serial No. 612,623.

To all whom it may concern:

Be it known that I, HOWARD TURNER BARNES, a subject of the King of GreatBritain, professor of physics, of McGill University, in ltlontreal, inthe Province of Quebec, Dominion of Canada, have invented certain newand useful Improvements in Methods of and Apparatus for Recording MarineConditions. of which the following is a specification.

My invention relates to improvements in method of, and apparatus forobserving marine conditions and more particularly for the precisemeasurement of water temperature, with the object of ascertaining thepresence of icebergs, shoals, and other causes of marine disturbances inthe near vicinity of a ves' 'l.

Itha been theoretically suggested that the presence of icebergs might bedetected by their cooling effect on the water, this cooling effectprobably being produced by the current of cool and light fresh waterrunning down from the iceberg, and spreading on the surface of thesurrounding water. Very little practical use has been made of thissuggestion, as navigators are divided in opinion as to its value, owingto the variable results obtained. Any data gathered to test the methodhas been by means of the ordinary drop bucket and thermome ter, whichcould not read closer than one tenth of a degree. These readings werealso taken a considerable distance apart owing to the speed of the ship,and as the temperature of the sea'fluctuates independently of the ice,it will be seen that such readings would be of very little value.

-VVith the method and apparatus presently to be described, it ispossible to accurately read temperatures to one thousandth of a degreeand to continually record such readings. .Experimental data covered bythis method and apparatus has revealed a curious and characteristiccondition of the sea temperature in the vicinity, of an iceberg, whichwas incapable of observation by the old methods. This is, that onapproaching an iceberg, the temperature first slightly rises and thenlowers-a characteristic fact which may be taken as an indication of thepresence of ice and whichcan be due, as far as can be seen, to no othercause. The cause of the slight rise in the temperature is not clearitmay be due to temporary reaction at the juncture of the fresh surfacecurrent from the iceberg and the sea water-or it may be due to thepresence or absence of definite organic life at said juncture. Toobserve this characteristic effect, it requires two conditions, providedby the present method and apparatus, namely: extremely accuratemeasurement of the temperature to within one thousandth of a degree, andthe continuous recording of the measurement taken.

In the practical carrying out of the invention, an electric resistancethermometer is employed controlled by the sea temperature and connectedto a resistance measuring apparatus which continuously records thefluctuations in resistance and consequently in temperature. A veryconvenient form of recording mechanism is the Callendar recordingcombined potentiometer and VVheatstones bridge, such as manufactured bythe Cambridge Scientific Instrument Co. Ltd. To adapt this instrument,however,

to sea use, it is necessary to replace the suspension galvanometer by aWeston portable galvanometer relay or equivalent device which will notbe affected by the motion of the ship.

A very convenient arrangement for the detection of icebergs is theprovision of two thermometers measuring the temperatures at the surfaceand lower down, which thermometers may, if desired, be differentiallyconnected so as to measure only differences in temperature. Where adifference in temperature exists between the two thermometers, it may betaken that it is due to some local causes such as icebergs.

The form of apparatus for carrying out the method is illustrated in theaccompanying drawings, in which:

Figure 1 is a diagrammatic view of the apparatus. Fig. 2 is a sectionalview of a form of thermometer which may be employed. Fig. 3 is adiagrammatic viewof the connections when two thermometers are employed.

In the drawings like figures of reference indicate corresponding partsin each figure.

Referring first to Figs. 1 and 2 of the drawings, A represents thethermometer which is of the electric resistance type. I have found thatgreater stability in the operation of the thermometer can be secured ifthe resistance wire is formed of iron instead of the usual platinum. Theformof thermometer illustrated, which is of course not essential to themethod as a whole, is one which I have especially designed for thepurpose. It includes concentric tubes 10 and 11 of heavy copper, theinner tube being flanged to form a space 12 between, within which theresistance coil 13 of the thermometer is lo- 'cated. This coil is offairly large resistance in order to render fluctuations more readilyperceptible. I have found one hundred ohms to be sufficient for thispurpose. The connections from the resistance coil lead through aradially extending tube 14 which has screw threaded engagement with aconnecting member 15 secured to the side of the tube 10 opposite anaperture therein. This thermometer is so placed as to be directlyaffected by sea temperature. For example it may be trailed through thewater at a. depth of a few feet below the surface. Otherwise it might besecured to the hull of the vessel below the water line.

According to the present invention, fluctuations in the resistance coilA are accurately measured and continuously recorded by apparatus locatedon the vessel. The ordinary Wheatstones bridge method of measuring theresistance has been found to be the most satisfactory.

In the diagrammatic connection in Fig. 1, B represents the operatingbattery and 15 a reversing key for the 'same, from which conductors 16and 17 lead to the junction points 18 and 19 of the resistances formingarms of the bridge. 20 and 21 represent two bridge wires which areadapted respectively for the observation of a single temperature, andfor operation of the continuous recording mechanism in the mannerhereinafter described, either one or the other of these bridge wiresbeing thrown into circuit by means of switches 22 and 23. The arms ofthe Wheatstone bridge are constituted by resistance coils C and D eachof resistance substantially equal to that of the thermometer coil A. Thethermometer coil itself forms, with a portion of the bridge wire, thethird arm of the bridge, while the fourth arm comprises the remainingportion of the bridge wire, a series of small resistances from one tenthto ten ohms, represented in the form of a resistance box E, acompensating wire F and a compensating coil G. The wire F is used toequalize the wire leading to the thermometer, wherever it may be placed,and comprises a loop of wire placed closely to the leads of thethermometer coil A and running side by side with them, whereby it willchange equally in temperature with the said leads of the thermometer,and will therefore change equally in resistance, and, being connected tothe o posite arms of the Wheatstone bridge, w1ll not affect the balancepoint. The coil G is nect the junction point 24 with a sliding con--tact 25 on the bridge wire 20, the type of galvanometer being such thatit will not be affected by the motion of the ship. I have found that aWeston portable galvanometer is suitable for this purpose. I represents,as a whole, a continuous recording mechanism for the fluctuations in theresistance, the type of instrument which I have found most convenientfor this purpose bein Callendars record, combined potent-imeter and-Wheatstone bridge type, such as manufactured by the CambridgeScientific Instrument Co. Ltd. The instrument is varied, however, fromthat manufactured by this company, by the substitution of a Westonportable galvanometer J for the suspension galvanometer and the use ofthe reversible motor K. However, this last is not essential. Therecording mechanism includes pulleys 26, 27 and 28, over which a threador cord 29 is stretched, the pulley 28 being adapted to be driven by areversible motor K which has a separately excited field from a battery30 and has an armature which may be rotated in either direction. Thethread or cord 29 carries a sliding contact 30 mounted on the bridgewire 20 and carrying a pen 31 adapted to make a record on a recordingdrum or sheet L. The galvanometer J is provided with contacts 32 and 33against which the extremity of the handle 34 is adapted to press whendeflected on either side, and so complete either of the two circuits 35and 36 which are adapted to send current through the armature inopposite directions and so effect a reversal thereof, the circuit 36including the battery 37 and the circuit 35 including the battery 38.The galva-nometer J is connected between the junction point 24 and awire 39 which parallels the bridge wire 21 and is adapted to beconnected thereto by the sliding contact 30. It will thus be seen thatwhen the galvanometer is, for example, deflected to the left, contact at32 is made and the battery 38 sends a current through the armature whichrotates in such a direction as to pull the contact 30 to a positionwhich will establish the balance on the bridge wire again, and bring thegalvanometer needle to undeflected position. When the needle isdeflected to the right, contact with 33 is made and the battery 37 isset in operation causing the motor to reverse and drawing the contact30' over to the other direction on the bridge wire, and so restores thebalance. In the operation of this part of the invention as a whole, thethermometer A is carried to any distance where it is required to measurethe temperature, provided a similar length of compensating wire F isrun. For instance, the thermometer may be fixed over the side of theship and trailed through the water at a distance of a few feet below thesurface, the wires assing through a suitable inclosing and protectingcovering, such as copper and lead tubing. The resistances in the box Eare then adjusted so as to enable.

the fluctuations in temperature to be measured on the bridge wire, thelarge changes in temperature being taken care of by changes in theresistance box E. As the thermometer is designed principally to measureextremely small changes in tem perature, the principal use of theresistances will be when working in water of different degrees oftemperature. The switches 22 and 23 enable either of the bridge wires 20or 21 to be thrown into circuit, the bridge wire 21 permittingtheseparate reading to be made on the galvanometer H, while the bridge wire20 continuously records the reading, the scales on the chart or drumbeing made to correspond.

In Fig. 3 a form of ap aratus is illustrated particularly useful f drthe detection of the presence of icebergs and in which two thermometersA and A are connected differentially, the former being located a shortdistance below the surface and the latter as deep down as it is possibleto place it, the object being to cause one thermometer to be affected bythe light surface currents and particularly by the currents of freshwater flowing from an iceberg, while the lower thermometer will measurethe temperature of the ordinary sea water, which will vary onlyslightly. The general arrangement of the connect-ion of the twothermometers is the same, two opposite arms of the bridge being formedby the thermometer coils A and A respectively, while the other two armsare formed by compensating coils F and F respectively and compensatingwires G and Gr respectively. In this way the galvanometer will bedeflected by any difference in resistance between the ther mometers.

lVit-h the apparatus above described it is possible to accurately andcontinuously register temperatures to one thousandth of a degree and tomake registration when the ship is going at full speed. As beforestated, it is only w1th such accurate and continuous measurements thatthe peculiar conditions present in the water when approaching aniceberg, namely a slightly raised temperature followed by a rapidlydecreased temperature, can be noted. The method and apparatus are alsouseful for a variety of other purposes. For instance, in hydrographicwork, boundaries of currents and their variations of position withtides, seasons and the like can easily be worked out from a series ofcontinuous temperature records of the type described. It has also beenfound that shoals, and the proximity of land appear to producedisturbances in temperature, which can be detected by the presentapparatus.

As many changes could be made in the above construction and manyapparently widely different embodiments of my invention, within thescope of the claim, constructed without departing from the spirit orscope thereof, it is intended that all matter contained in theaccompanying specifications and drawings shall be interpreted asillustrative and not in a limiting sense.

What I claim as my invention is:

The method of determining the proximity of icebergs, etc., at sea, whichconsists in immersing in the water a thermometer getting an accuraterecord of the readings of said thermometer and deducing from certainpeculiarities of said record the proximity of such icebergs, etc.

In witness whereof I have hereunto set my hand in the presence of twowitnesses.

HOWARD TURNER BARNES.

Witnesses:

CHAS. F. DICKERSON, CHAS. ISAACS.

